Method for producing cyclohexanol

Abstract

The invention provides a method for preparing cyclohexanol from cyclohexyl carboxylate serving as raw material by performing an ester exchange reaction under a near critical or supercritical condition. According to the method, a catalyst is not used, reaction products do not need to be separated in the reaction process, and low alcohol-to-ester ratio can be adopted; furthermore, the method has the characteristics of high reaction rate, high conversion rate, high selectivity and simple aftertreatment.

Description

technical field [0001] The invention relates to a method for producing cyclohexanol, in particular to a method for producing cyclohexanol by transesterification under near-critical or supercritical conditions. Background technique [0002] Cyclohexanol is a widely used chemical raw material and solvent. For example, cyclohexanol can undergo dehydration reaction at high temperature (such as 150°C to 300°C) to prepare cyclohexene. Among the many uses of cyclohexanol, the most important is cyclohexanone, the main intermediate in the production of nylon 6. [0003] Since the advent of nylon, DuPont, DSM, Monsanto, BASF, Sumitomo, Toray, Asahi Kasei and other world-renowned chemical companies have long been committed to the development of cyclohexanol (ketone) production technology. At present, the industrial production methods of cyclohexanol (ketone) include phenol hydrogenation method, cyclohexane oxidation method and cyclohexene hydration method. [0004] The phenol hydroge...

AI Technical Summary

Problems solved by technology

These documents show that biological enzyme catalysis cannot be applied industrially in the short term because it is difficult to solve the problem of high catalyst cost and easy deactivation; the reaction rate of acid catalysis is slow, and the use of acid catalyst will also cause serious equipment corrosion and Pollution emission, the alcohol in the reaction system may also undergo etherification reaction under acid catalysis conditions; base catalysis has the advantages of mild reaction conditions and fast rate, but it is only suitable for raw materials with high purity, especially raw materials that cannot contain acid and and / or water, otherwise it will adversely affect the base catalyst

In addition, if homogeneous catalysis is used, there must be post-treatment steps such as neutralization, water washing, and drying, while heterogeneous catalysis (solid catalyst) is still in the stage of industrial testing, and there are no reports on the industrial application of heterogeneous catalysis in the literature.